In vitro interactions of titanium bioalloys with human cells and physiological fluids

Studies concerning the long-term electrochemical behavior in artificial saliva and interactions with fibroblasts of Ti-45.5Ni bioalloy are performed in this paper. Titanium and its Ti-45.5Ni alloy revealed a typical passive metal behavior in Tani&Zucchi (of pH=2.5 and 7) and Fusayama (pH=5.5) artificial saliva. Breakdown (pitting) potential has electropositive values that can not be reached in oral cavity. Corrosion potentials for Ti-45.5Ni alloy in Carter-Brugirard saliva presented more electronegative values than titanium, but no form of local corrosion was registered during 4000 exposure hours. Corrosion potential gradients simulated for saliva composition non-uniformity have low values, showing very good corrosion resistance. Human embryonic fibroblasts rapidly adhered (72% cells in 48 hours) on Ti-45.5Ni alloy surface. Cell proliferation is considerable in the first 48 hours of culture. Slight cytotoxic effects specially developed after 72 incubation hours